However, the response consists of 250 items and hardly any of them have a score of more than 30. In fact, only two of them do. This is verified by removing the /unanswered qualifier and running the following request:

This route does indeed return the correct number of items (currently 26) and each of them has a score >= 30 as expected. Obviosuly if there are only 26 total questions that have a score >= 30 then there cannot possibly be more unanswered questions than that.